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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 26 |
| 4 | 104 |
| 5 | 429 |
| 6 | 1803 |
| 7 | 7782 |
| 8 | 33856 |
| 9 | 148730 |
| 10 | 660726 |
| 11 | 2948863 |
| 12 | 13237899 |
| 13 | 59758894 |
| 14 | 270693518 |
| 15 | 1230751350 |
| 16 | 5614377090 |
| 17 | 25678567655 |
| 18 | 117745736266 |
| 19 | 541132227323 |
| 20 | 2491918243663 |
| 21 | 11496651079775 |
| 22 | 53130402214928 |
| 23 | 245919723193033 |
| 24 | 1139897903189075 |
| 25 | 5290724990386423 |
| 26 | 24586936743438214 |
| 27 | 114391228364278238 |
[1,2,7,26,104,429,1803,7782,33856,148730,660726, 2948863,13237899,59758894,270693518,1230751350, 5614377090,25678567655,117745736266,541132227323, 2491918243663,11496651079775,53130402214928, 245919723193033,1139897903189075,5290724990386423, 24586936743438214,114391228364278238] |